The correct answer is B. 8 bits in a byte.
A bit is the basic unit of information in computing and digital communications. It is a binary digit, the smallest increment of data on a computer. A bit can be either a 0 or a 1, representing the electrical values of off or on, respectively.
A byte is a group of 8 bits. It is the basic unit of information in many computer systems. A byte can represent a number, a letter, or a symbol.
The other options are incorrect. Option A is incorrect because a byte has 8 bits, not 16. Option C is incorrect because a byte can have any value from 0 to 255, not just 255. Option D is incorrect because a byte is not a decimal number, it is a binary number. Option E is incorrect because 2 to the 9th power is 512, not 8.